        body,dl,dd,ul,ol,h1,h2,h3,h4,h5,h6,p,form{margin:0}
        ul{list-style-type: none;}
        p{text-indent: 2em;}
        body,button,input,select,textarea{font:12px/1.5 tahoma,'\5b8b\4f53',sans-serif}
        h1,h2,h3,h4,h5,h6{font-size:100%}
        em,b{font-style:normal}
        a{text-decoration:none}
        a:hover{text-decoration:underline}
        img{border:0}
        button,input,select,textarea{font-size:100%;outline:none}
        table{border-collapse:collapse;border-spacing:0}
        td,th,ul,ol{padding:0}

        @keyframes fadein {
            from{
                opacity:0;}
            to{
                opacity: 1;}
        }

        #introduce,#playInt,#gameInt{
            width:80%;
            margin:10%;
			box-sizing:border-box;
            margin-top:30px;
            border-top:1px solid gray;
        }
        h1{
            width:130px;
            height:30px;
            position: relative;
            top:-25px;
            font-size:30px;
            background-color: white;
        }
        img{
            width:100%;
        }
        #playInt ul.playBtn li{
            float:left;
            width:33.3%;
            text-align: center;
            border:1px solid #000;
            background-color: grey;
            box-sizing:border-box;
            cursor: pointer;
        }
        #playInt ul.playBtn li:nth-last-child(1){
            width:calc(100% - ( 33.3% + 33.3%));
        }
        #playInt ul.playBtn  li.active{
            border-bottom: none;
            background-color:inherit;
        }
        #playInt ul.playPic li{
            display:none;
            width:100%;
            border: 1px solid #000;
            border-top: none;
            overflow: hidden;
        }
        #playInt ul.playPic li.show{
            display:flex;
            align-items: center;
            box-sizing:border-box;
            animation:fadein 1s;
        }
        #playInt ul.playPic li img{
            float:left;
            width:30%;
            padding:20px;
        }
        #playInt ul.playPic li p{
            position: relative;
        }

        footer{
            display: flex;
            width: 100%;
            height: 100px;
            background-color: lightgray;
        }
        footer div*{width:20%;}

        footer .office{
            float: left;
            position: relative;
            min-width: 160px;
            left:20%;
        }
        footer .social{
            position: absolute;
            min-width: 160px;
            right:20%;
        }




